Pressure casting apparatus



April 7, 1964 H. FLECKENSTEIN ETAL 3,127,644

PRESSURE CASTING APPARATUS Filed June 27, 1960 2 Sheets-Sheet 1 Fly. 1

Jnvenlor:

//,4N5 FLECKE/VSTE/N GUNTHEE HAAG mun April 7, 1964 H. FLECKENSTEIN ETAL3,127,644 PRESSURE CASTING APPARATUS Filed June 27, 1960 2 Sheets-Sheet2 H/z/vs F4 [Chf/VS TF/N GUNTHER HAAG United States Patent mazes-4PRESSURE CASTlNG APPARATUS Hans Fleckenstein and Gunther Haag, @ldenhurgin Gidenhurg, Germany, assignnrs to Lieentia Fatent VervvaltungsG.rn.b.H., Frankfurt am Main, Germany Filed June 27, 196i Ser. No.39,133 Claims priority, application Germany July 1, H59 3 Claims. (or.22-68) The present invention relates to a pressure casting apparatushaving a multiple arrangement of molds on a feed mechanism, moreparticularly to a pressure casting apparatus wherein the mold iscomprised of several portions with the bottom portion being fixedlymounted on the apparatus and the upper portions being arranged on afeeding mechanism for successively engaging the fixed lower moldportion. In those instances where the mold is comprised of a pluralityof portions one of the portions may be mounted on a mold closing plateand other portions may be rigidly attached to those parts of the castingapparatus which are not included in the feeding mechanism.

The pressure casting apparatus of this invention is of the type whereinthe molds are moved in a horizontal direction for closing and openingthe molds. A plurality of molds are employed in order to increase theoutput of the casting apparatus.

While many different kinds of pressure casting machines have beendevised, most of the improvements are concerned with the mechanism foropening and closing the mold, the pressure cylinder, the filling andpressure chambers, and the relationship of these components with respectto each other. The different kinds of casting machines are devised forparticular purposes, such as to readily accommodate a particular castingmaterial, for making either large or small castings, for employingeither single or multiple molds, and for the use of complicated moldseither with or without inserts.

In addition, pressure casting machines have been devised solely for thepurpose of increasing the output of castings per unit time. One form ofa high production pressure casting machine comprises arranging aplurality of either filling chambers, pressure chambers or feeding unitsso that these components are moved successively into working positionwith respect to one of the molds. In another form of the high productioncasting machine a plurality of similar molds are moved successivelybeneath the discharge opening of a crucible and are successively filledwith the casting material.

Both of the above described high production casting machines employdifferent auxiliary devices since in one case the purpose is to decreasethe time of feeding the casting material While as in the other instancethe total time for casting is decreased by the use of a plurality ofmolds.

It has been found that the most economical use of a pressure castingmachine is attained by using a machine comprising a plurality of molds.The present invention relates to such a pressure casting machine and hasgreat advantages over known pressure casting machines even though theconstruction of the present machine is considerably simplified. Inaddition, the present pressure casting machine has features other thanmerely arranging a plurality of molds in a feeding mechanism which movesthe mold successively into a casting position.

In the present invention exchange mold halves are arranged on a feedingmechanism which is capable of moving the mold halves into and out ofengagement with a single stationary mold half which is secured on thepressure cylinder of the casting machine. If the mold is comprised ofmore than two portions, the exchange portions of the mold are mounted onthe feeding mechanism.

3,127,644 Patented Apr. 7, 1964 The feeding mechanism is also capable ofrotary movement so as to successively move the exchange mold halves intooperative position with the stationary mold half to conduct a castingoperation. During each casting cycle the castings are removed from theexchange mold halves and these halves are prepared for a subsequentcasting process. The number of cycles of operation and the sequence ofthe cycles is determined by the type of casting to be accomplished.

A four cycle sequence is preferable for castings of medium sizecomprising a light metal in which iron inserts are employed. In thissequence the following cycles occur:

(1) The actual casting of the material and cooling of the material tosolidification;

(2) Ejection or removal of the casting from the mold;

(3) Cleaning of the mold;

(4) Positioning of the insert in the exchange mold half.

The stationary mold half is always cleaned following each castingoperation by an automatic mechanism which moves into and out of positionafter each cycle of the casting process.

The present invention is not limited to the use of molds comprising onlytwo parts. It is also possible to use molds comprised of three portionsproviding the cast ing mold is closed in one axial direction. When threepart molds are employed, the central part of the mold acts similarly tothe exchange mold half in the two part mold and the exchange part of thethree part mold which like the lower mold part is needed only during theactual casting operation is mounted on the mold closing plate positionedopposite the stationary mold part. The stationary mold part is attachedsuch as by screws to the stationary platen.

When a mold is employed having more than three parts the additionalparts are generally fixed to the feeding mechanism of the pressurecasting machine. However, in some instances, additional mold parts canbe mounted on stationary portions of the casting machine which portionsare other than the feeding mechanism.

Another feature of the pressure casting machine of this invention is theconstruction of the feeding mechanism so as to comprise an annularmember which is rotatably mounted and is rotated by means of powertransmitted through a gear system drivingly engaging an internal gear onthe annular member. The exchange mold halves are mounted on the annularmember so that rotation of the annular member will successively move theexchange mold halves into position for the casting operation. Theopening and closing of the mold is achieved by movement of the feedingmechanism, including the annular member, toward and away from thestationary mold half which is fixedly mounted on the casting apparatus.

In order to prevent any bending of the annular member during the openingand closing of the mold, the movement of the movable plate issynchronized with movement of the annularmember. This synchronizationoccurs during the last stages of the mold closing movement and theinitial stages of the mold opening movement. This synchronization isachieved by supporting the piston rod of the hydraulic cylinder, whichmoves the annular member, on an arm extending from the mold closing endplate.

It is therefore the principal object of this invention to provide anovel and improved pressure casting machine which is capable ofincreased production but which has a simplified construction.

It is another object of this invention to provide a high productionpressure casting machine wherein a plurality of exchange mold halves aresuccessively brought into a 3 casting position with respect to a fixedlymounted i.e. stationary mold half.

Other objects and advantages of this invention will become apparent uponreference to the accompanying description when taken in conjunction withthe following drawings:

FIG. 1 is a front elevational view of the pressure casting apparatus ofthis invention;

FIG. 2 is a top plan view of the pressure casting apparabus; and

FIG. 3 is a sectional view of the pressure casting apparatus taken alongthe line 33 of FIG. 1 and looking into the direction of closing themold.

With reference to the drawings wherein like reference symbols indicatethe same parts throughout the various views, a specific embodiment ofthe pressure casting apparatus of this invention will be described.

With respect to all iigures an annular member 1 is mounted within astationary frame 2 which is a component of the pressure castingapparatus. The pressure casting apparatus further comprises a frame 29secured to frame 2, a pressure cylinder 3 for feeding the castingmaterial into the mold, a stationary platen 4 on which the bottomportion of the mold is mounted, a movable mold closing end plate,(movable platen 5) which is aligned with the stationary mold half, and aplurality of pairs of guide rods 6. The inner surface 31 of the annularmemher 1 having a gear ring 3 1, is rotatably mounted on two pairs ofrollers 7 and 8 with the rollers being mounted inside of a bearinghousing 9.

The non rotatable bearing housing is movably mounted, and movement iseifected by a piston rod 11 of a power piston, housed in stationarycylinder 11. The bearing housing 9 engages member 1 and it is slidablymounted on rods 12 which extend between portions of the frame 2.

Housing "9 is secured to rod 10. Frame 2 is substantially comprised oftwo walls secured to each other by means of bolts 24. The annular member1 is rotated through a power transmitting system which comprises a rackand pinion gear arrangement 13, wherein the rack is connected with acontrol piston and cylinder arrangement which is not illustrated. Thepin-ion gear 26 is operated upon by the rack and is in turn drivinglyconnected to a sprocket 25, which in turn is driving a chain 14, adriving gear 15, and the latter is dnivingly engaged with gear teeth 16on the inner surface 31 of the annular member 1, so as to form aninternal gear. It will be apparent from the foregoing, that the rack andpinion arrangement 13 rotates member 1, while piston rod Ill displacesmember 1 in axial direction.

A plurality of exchange mold halves 1'7, in this instance four, aremounted on the annular member 1 with the number of the mold halvescorresponding to the cycles of the sequence of operation of the castingprocess, as will be subsequently described, when the castings remain inthe exchange mold halves upon the opening of the molds.

A single stationary mold half 18, which completes the mold with any ofthe exchange mold halves 17, is mounted by screws onto the stationaryplaten 4. There is a control disc 27 for the entire machine.

In order to close the mold, the mold feed mechanism which comprises theannular member 1 with housing 9 and molds 17, is first moved by thepiston rod of the cylinder 11 towards the stationary mold half r18. Themovable platen 5 having a block 31 is moved, in FIGS. 1 and 2 of thedrawing to the right, and holds the mold closed during the actualcasting process. The mold is closed by means of conventional L-shapedlevers 2x8 urging platen 5 towards that one of the exchange mold halfs17 which already engages stationary mold half 18. Platen 5 is guided onand along rods 6. In closed position of the mold the end of an arm 19which extends from platen 5, engages the outer end of the piston rod 10and thus additionally completes the mold closing movement. Thus, themold is actually closed by the arm 10. In the same manner the arm 1'9prevents a premature opening of the mold when the opening of the mold iscaused by movement of the feed mechanism through means of the cylinder'11. Thus, it can be seen that during both the opening and closing ofthe mold, any bending of the annular member 1 on its guides 12 isprevented.

Arm 19 also prevents an advancing of the opening by means of pistons 11,because even during the opening process rod 16 still rests against arm19. Rod 10 can follow only the retracting movement of platen 5 inkeeping engaged with arm 19. In any of these cases, bending of member 1or its clamping on rods 12 is effectively prevented.

Upon returning the feed mechanism to its starting position after themold has been opened following the casting operation, the annular member1 is rotated by an angle of by the power transmission system (rack andpinion gear 13) in a counterclockwise direction as viewed in FIG. 3 ofthe drawings. Accordingly the second one of the exchange mold halves 17is positioned in front of the stationary mold half 18. During the rotarymovement of the annular member 1 a nozzle arrangement 20 is moved infront of the bottom mold half by a piston 21 to clean the bottom moldhalf by compressed air discharged from the nozzle arrangement 2b. Inactual practice, the nozzle arrangement 20 comprises a plurality ofnozzles positioned to cover the entire inner surface of the bottom moldhalf. immediately after completing the cleaning of the stationary moldhalf 18, the nozzles 20 are returned to their original position which isshown in FIG. 1 of the drawings.

While the second exchange mold half 17 is being moved into a moldclosing position after rotation of the annular member through 90, thecasting which has now cooled is ejected from that one of the exchangemold halves now containing the casting. Ejection is carried out by thepiston rod 22 of the removal or ejection cylinder 23, which rod 22pushes towards the right for such ejection. This ejection occurs whenthe casting is in its second position. As seen in FIG. 3 of the drawingsthe second position is shown as the uppermost of the exchange castinghalves 17.

In the third position of the member 1, the exchangeable mold half is inthe left hand position as seen in FIG. 3, and thus exchange mold half iscleaned such as by applying compressed air against the surfaces thereof.

In the fourth position any inserts which are to be placed in the castingare inserted in the exchange mold half. Such inserts may comprise bridgeportions for rotors of electric motors.

The exchange mold half with the inserts in place is then rotated intothe number 1 or casting position which is the right hand position asseen in FIG. 3 of the drawmgs.

Thus, it can be seen that the present invention provides a highproduction pressure casting apparatus which is extremely simple inoperation and construction. Further, the minimum of moving partsprovides for long troublefiree operation and reduces maintenance costsand downtime of the apparatus. It is to be borne in mind that the number\of upper mold halves mounted on the annular member can be varied inaccordance with the various steps which are to be conducted during thecasting operation. Further, the use of the casting apparatus of thisinvention is not limited to molds comprising two parts, but may bereadily adapted for use with molds having three or more parts.

It will be understood that this invention is susceptible to modificationin order to adapt it to different usages and conditions, and,accordingly, it is desired to comprehend such modifications within thisinvention as may fall within the scope of the appended claims.

We claim:

1. in a pressure casting apparatus having a multiple mold arrangement,the combination of a stationary frame, a stationary mold half secured tosaid frame, a pair of parallel rods mounted on said frame, a bearinghousing slidably mounted on said rods, two pairs of rollers mountedinside and on said bearing housing, an annular member rotatablysupported on its inner annual surface by said two pairs of rollers, anda plurality of exchange mold halves mounted on said annular member andcapable of both rotary movement and movement toward and away from saidstationary mold half for casting operations, said rods extending in thedirection of said last mentioned movement.

2. -In a pressure casting apparatus as claimed in claim 1 wherein saidannular member comprises an internal gear, a driving gear meshing withsaid annular disc internal gear, a rack and pinion gear arrangement, anda driving chain connecting said pinion gear and said driving gear totransmit power from said rack and pin-ion to said annular disc.

3. In a pressure casting apparatus the combination as claimed in claim1, comprising, in addition; a stationary power cylinder; a piston rod insaid cylinder connected to said housing for engaging said member.

References Cited in the file of this patent UNITED STATES PATENTS1,239,808 Morris Sept. 11, 1917 1,989,812 Lester Feb. 5, 1935 2,054,476Derry Sept. 15, 1936 2,329,346 Golf Sept. 14, 1943 2,476,219 PurintonJuly 12, 1949 2,570,325 Dalton Oct. 9, 1951 2,848,771 Eggenberger Aug.26, 1958 3,063,108 Gardner Nov. 13, 1962

1. IN A PRESSURE CASTING APPARATUS HAVING A MULTIPLE MOLD ARRANGEMENT,THE COMBINATION OF A STATIONARY FRAME, A STATIONARY MOLD HALF SECURED TOSAID FRAME, A PAIR OF PARALLEL RODS MOUNTED ON SAID FRAME, A BEARINGHOUSING SLIDABLY MOUNTED ON SAID RODS, TWO PAIRS OF ROLLERS MOUNTEDINSIDE AND ON SAID BEARING HOUSING, AN ANNULAR MEMBER ROTATABLYSUPPORTED ON ITS INNER ANNUAL SURFACE BY SAID TWO PAIRS OF ROLLERS, ANDA PLURALITY OF EXCHANGE MOLD HALVES MOUNTED ON SAID ANNULAR MEMBER ANDCAPABLE OF BOTH ROTARY MOVEMENT AND MOVEMENT TOWARD AND AWAY FROM SAIDSTATIONARY MOLD HALF FOR CASTING OPERATIONS, SAID RODS EXTENDING IN THEDIRECTION OF SAID LAST MENTIONED MOVEMENT.